Sarcoidosis and Crohn disease are chronic granulomatous conditions of unknown pathogenesis that affect multiple organ systems. A common mechanism has been proposed but never proved. Recently, it has been suggested that human herpesvirus 8 (HHV-8) might play a role in the pathogenesis of sarcoidosis based on polymerase chain reaction studies showing HHV-8 in a high proportion of affected tissues.1 We used polymerase chain reaction studies to amplify a 233–base pair fragment of HHV-8 DNA in archived specimens of tissues from patients with sarcoidosis and Crohn disease who had never been treated with corticosteroids or immunomodulator agents to determine if HHV-8 might be present in these tissues.